城市快速路通行能力再认识与新分析体系构建

为了解决目前城市快速路通行能力理论与经验研究中存在的3个问题，基于上海城市快速路与美国加州快速路的大量实测数据，从期望通行能力、随机通行能力、动态通行能力与运行通行能力4个方面系统梳理了快速路通行能力的计算方法。研究结果提出依次采用失效前稳定流率、考虑删失数据的生存分析方法、综合考虑动静态影响因素的多层统计分析模型、不同时间占有率/速度区间下的威布尔分布来估计上述4类通行能力；构建了一套适用于城市快速路规划、设计、运行与管理几个不同阶段的通行能力新分析体系，旨在为快速路生命周期全过程的通行能力计算提供关键技术支撑；对比分析国内外基本通行能力研究结果，从规划设计角度给出了基本通行能力的新定义：在通常的道路、交通与管控条件下，某一点或均匀断面，在15%的失效概率下，所容许通过的5 min失效前稳定流率。

Revisit of Capacity Model and Reconstruction of Capacity Analysis Framework at Urban Expressway

To solve three typical problems for the capacity studies in current theoretic and empirical studies, based on the detector data on urban expressway in Shanghai, China and Sacramento, US, the four different capacity definitions and calculation methods were studied from expected capacity, stochastic capacity, dynamic capacity and operational capacity. The results recommend to adopt pre-queue flow before traffic flow breakdown, survival analysis of censored data, multilevel models of dynamic and static factors and Weibull distribution of different time occupancy or speed to estimate the expected capacity, the stochastic capacity, the dynamic capacity and the operational capacity. Secondly, the new capacity analysis framework is proposed for the different usages at expressway planning, designing, operation and management which covers the whole life-cycle process of urban expressway and supply the fundamental support of capacity calculations. Finally, based on analyze the domestic and foreign basic capacity results, from the perspective of planning and design the new definition of basic capacity is redefined as follows:the capacity is the 5 min pre-queue flow rate along a point or uniform roadway segment corresponding to the 15% probability of breakdown deemed acceptable under prevailing roadway, traffic, and control conditions.